This circuit was found in a 90s Popular Electronics. It is used for the acoustic transmitters of 40 kHz, as several found in this section. Transistors support current equivalents.
16 commercial test circuit for tubes and transistors appeared in Radio Electronics magazine in...
Suggested by an American publication, this circuit has 5 operating conditions indicated in the...
This circuit with an integrated circuit of the time was found in the magazine Radio Electronics of April...